When Bangkok’s futuristic $4 billion (2.5 billion pound) Suvarnabhumi airport opened six years ago, it was hailed as a model for the region.

Today, it is beset by two-hour immigration queues, passenger numbers far beyond capacity and a crisis over management.

Immigration queues have grown so long travellers have been told to arrive three hours before a flight, an hour longer than in most air hubs, threatening to damage Thailand’s tourist-friendly image.

The problems have become so acute in recent days that the government is trying to convince growing numbers of low-cost carriers to move operations to Don Muang, a domestic airport.

And:

The immigration bureau has in the past blamed long queues on a staffing shortage. An official at Suvarnabhumi’s immigration division, however, said it had more to do with lack of space.

“There’s construction going on which is limiting the space we have available for security checks,” he said, declining to be identified.

But travellers grumble at the frequent site of empty immigration kiosks and lines for foreigner nationals stretching far longer than those of Thais. Others say kiosks designed to hold two officers are often manned by one.

Some airlines expressed concern and confusion on Friday over an announcement a day earlier by Thailand’s transport minister, Jarupong Ruangsuwan, to move flights to a different airport.

Thai Airways, in a memo this week to travel industry partners, said passengers should arrive three hours before their departure time. For arriving passengers, it noted that processing visas at immigration now takes two hours on average.

And:

There is a shortfall of more than 200 immigration officers at Suvarnabhumi because many are reluctant to work at the overcrowded airport.

“It is a very stressful job — there’s no doubt about it,” said Imtiaz Muqbil, executive editor of Travel Impact Newswire, a trade publication.

He told The Straits Times: “Most of the officers are not very good in English. They get overwhelmed by the complexity and sheer scale of the traffic, and the risk of making a mistake.”

Earlier this week, Airports of Thailand (AOT), which runs the terminal, agreed to raise the overtime pay of immigration officers as an additional incentive.